"I'm afraid we're not going to blow anything up or set anything on fire," said Grant Imahara, a co-host of the popular show on the Discovery Channel.

Cries of protest came from the audience at Spragins Hall. After all, blowing stuff up is one of the things "Mythbusters" does best.

"It's hard to get that (explosive) stuff past all the TSA guys," Imahara said as he delivered the punchline to his opening joke. "I know. I've tried."

What followed was an amusing journey through Imahara's career as a behind-the-scenes guy in high-profile movies and commercials you probably know all too well.

He also hit some "Mythbusters" highlights, including the show's investigation into whether the 1969 moon landing was genuine or simply the greatest con job of all time. Indeed, part of that episode was filmed in Huntsville in 2008.

"It's not a hoax," Imahara told his approving audience. "Believe me, we proved all the data."

While "Mythbusters" has brought Imahara into prominence, the most interesting part of his 70-minute presentation were things you were familiar with.

But maybe you didn't realize that it was Imahara who put the energy in the Energizer bunny. Or maybe you weren't aware that Imahara was one of the three people it took to operate R2D2 in the three most recent "Star Wars" movies.

On the pink bunny that keeps going and going in the Energizer commercial, Imahara entered the special effects picture when the company had a dispute with the original developer of the bunny.

That resulted in Eveready, the company that produces the Energizer batteries, needing to build new bunnies.

"The electronics (that operate the bunny) were in the drum," Imahara said. "That was my job."

Turns out it takes 44 double-A batteries - "They are Energizer batteries," Imahara confirmed - to operate the bunny. And three people, including Imahara, whose job was to make sure the arms operated as expected.

The bunnies are about two feet tall because to make them smaller would be difficult because of all the electronics inside. And there are three bunnies: Earl, Floyd and Garth.

"I can't tell you how much they cost," Imahara said. "But if you know what a Ferrari Testa Rossa costs, each bunny costs that much."

Imahara is also an "official operator" of R2D2 - a distinction that came about when additional operators were needed for the robot to make personal appearances.

Something to watch for, Imahara pointed out: When you see the two-legged R2D2, there is usually an actual person inside operating the robot. Actor Kenny Baker did the honors in the movies. But when you see a third leg appear, it's the robot being operated remotely.

In all, there are 13 R2D2 robots and Imahara worked on the electronics of each.

"It's easier to drive than the Energizer Bunny," he said.

And finally, Imahara told of being an occasional stand-in for R2's buddy C3PO. For a guy who grew up a huge "Star Wars" fan - "I had the bed sheets and the lunchbox" - getting to be a stand-in on the red carpet when the original "Star Wars" was re-released led to a memory of a lifetime.

Actress Carrie Fisher - who played Princess Leia in the movies - approached C3PO and "It was a geek-asm," Imahara said.

But Fisher, Imahara said, knew exactly where to look for the slits for C3PO's eyes and knew it wasn't actor Anthony Daniels, who portrayed the robot in the movies.